Process and apparatus for the wet treatment of lengths of textile materials and the like



June 1969 c. A. MEIER-WINDHORST ET AL v 3,451,077

PROCESS AND APPARATUS FOR THE WET TREATMENT OF LENGTHS 0F TEXTILE MATERIALS AND THE LIKE Filed April 14, 1967 Sheet or 2 Fig. 2

Fig.1

INVENTOR (IIRISTMN AUGIUT HFIE'R- U/fiDl/ORST ATTORNEY J 24, 1969 c. A. MEIER-WINDHORST ET AL 3,4

PROCESS AND APPARATUS FOR THE WET TREATMENT OF LENGTHS OF TEXTILE MATEHLALS AND THE LIKE Filed April 14, 1967 Sheet ,3 of 2 Fig.3

INVENTOR (/msr/A Aacasr MEIER-0010110951- ET AL.-

United States Patent Int. Cl. D06c 1/00; D06f 31/00 US. Cl. 8-151 2 Claims ABSTRACT OF THE DISCLOSURE A length of textile material is washed or otherwise wet treated by being passed consecutively through several baths and by being squeezed after its passage through each bath, the squeezing being carried out in two stages to initially remove the liquid film carried by the fabric and then removing the liquid located in the fabric. The removed liquid is directed into the bath from which the fabric has just emerged to prevent it from being mixed with other baths.

This invention relates to a wet treatment, such as washing, of moving lengths of textile materials and to an apparatus for carrying out this process.

It is known in prior art to subdivide washing, acid removal and similar treatments into several separate treatment sections and to provide intermediate squeezings between these sections.

In the course of these treatments the bath liquid pressed out of the goods usually flows along the length of the goods back to the preceding treating section. It was found that such removal of the squeezed out liquid has most detrimental effects upon the results of the respective wet treatment. In order to provide best possible results for the treatment of the goods it is often necessary to provide proper conditions for the treating bath and for the bath liquid pressed out of the goods and to attain this the bath must be precisely conditioned. This cannot be achieved with the intermediate squeezing of the type used in prior art, wherein an undefined mixture of the bath from the preceding treating section which is located upon the goods and of the liquid located in the goods which is to be washed out, flows back into the preceding section.

An object of the present invention is to eliminate the drawbacks of prior art methods and devices.

Another object of the present invention is to process in the best possible manner the actual squeezed out bath produced at the squeezing joint, that is, to separate it from the liquid entrained by the goods as a surface film and to reintroduce it again into the treating process in locations best suited to attain best possible treatment results.

Other objects of the present invention will become apparent in the course of the following specification.

In the attainment of the objectives of the present invention it was found desirable to improve the process for the wet treatment of moving lengths of textiles and the like, wherein the entire treatment is subdivided into several treating sections by subjecting the goods after they have passed through the treating bath of each treating section to a liquid removing treatment in such manner that the baths of the various treating sections remain separated. The treating bath liquid is advantageously directed in countercurrent to the direction of movement of the length of fabric and the entire treatment is divided into at least 5 to 8 treating sections with at least 8 separated baths.

Theoretical investigations have shown that the ratio of the liquid which is transported by the fabric in its direction of movement through the separated baths to the treating liquid flowing in the opposite direction, the volume of which is determined by specific liquid consumption, has a decisive influence upon the output of the treatment, whereby this ratio should be as small as possible. Therefore, the liquid removal should be carried out by high output squeezing with a 65-70% squeezing effect. It was found to be particularly advantageous to carry out the high output squeezing in two stages, namely a preliminary squeezing for the removal of the surface liquid and a main squeezing for the removal of the surface liquid and a main squeezing for the removal of liquid located in the core of the fabric. When there are eight separate baths, at least four high output squeezings should be provided between the treating sections. In the other sections lighter squeezings can be provided.

A constant concentration gradient between the textile fabric and the treating bath, or one which changes only continuously, should exist in the treating sections through which the fabric is passed. The bath liquids removed preferably at the squeezing locations of the individual treating sections must be reintroduced into the flow of the treating bath at places having the same or similar concentration.

The process of the present invention provides an ideal possibility for the automatic regulation of washing machines, since the concentration of the bath in the main squeezing device has a direct connection with the concentration in the fabric itself which is still present. Measuring sensing devices for the regulating apparatus may consist, for example, of conductivity electrodes, pH-measuring devices or devices for measuring turbidity of the bath, of the type well known and generally used. A regulator can regulate the speed of the fabric, the supply of fresh water or the addition of chemicals, depending upon the results of these measurements, for example, depending upon the difference between an actual value and the required value.

A wet treating apparatus constructed so as to be capable of carrying out the process of the present invention must be provided with a two step intermediate squeezing device for preliminary and main squeezing behind each treating section or treating range. The part of the intermediate squeezing device intended for main squeezing is preferably constructed as a horizontal two roller squeezer, whereby one roller of the main squeezing section cooperates with a light roller of the preliminary squeezing section.

However, the objects of the present invention will be also attained if the device for the preliminary squeezing is arranged separately from the device for the main squeezing.

The invention will appear more clearly from'the following detailed description When taken in connection with the accompanying drawings, showing by way of example, preferred embodiments of the inventive idea.

In the drawings:

FIGURE 1 illustrates diagrammatically a washing section with an intermediate squeezer wherein the preliminary squeezing section constitutes a single unit with the main squeezing section.

FIGURE 2 illustrates diagrammatically a separate arrangement of the preliminary squeezing section from the main squeezing section.

FIGURE 3 illustrates diagrammatically a washing plant for solution washing constructed in accordance with the present invention.

The drawings show a bath 12 located in washing sections and used, for example, for the washing of a length 19 of a textile material. This length of material is guided by upper and lower rollers 11 through the Wash ing sections. An intermediate squeezer is located behind each washing section.

As shown in FIG. 1 each squeezer includes two horizontal rollers 13 located next to each other for the main squeezing and a roller 14 for the preliminary squeezing which cooperates with one of the rollers 13. The length of material passes through the preliminary and main squeezing sections and extends over a guide roller 15; it can also be guided over a broad holder 16. Guiding sheets 17 are located under the rollers 13, so that the liquid dropping from the rollers 13 is guided back into the washing section 10.

The device shown in FIG. 2 differs from the device of FIG. 1 substantially in that FIG. 2 shows an intermediate squeezer wherein the rollers 18 used for the preliminary squeezing are separated from the rollers 13 for the main squeezing.

The devices shown in FIGS. 1 and 2 may operate by producing in the preliminary squeezing section a light preliminary squeezing of 150 to 200% and in the case of high speeds of about 100 to 120%. The layer of liquid which moves along with the fabric and which does not have a concentration substantially greater than the wash water in the preceding compartment, is then removed and can be guided back into that washing compartment. Thus this liquid can not dilute any more the liquid pressed out in the main squeezing section and thereby prevent its further use on account of a greater drop in concentration. After the preliminary squeezing the fabric passes through the main squeezing section wherein a squeezing takes place of from 100 to 120% to 80 to 90% with exchange of concentration in the material. As shown in FIGS. 1 and 2, the main squeezing section preferably consists of two horizontal squeezing rollers 13. The arrangement of the rollers and the manner of guiding the fabric make possible an easy collection and removal of the concentnated liquid which is removed in small amounts. This liquid does not flow along the fabric and thus can not dirty the fabric. 011 the other hand, in prior .art squeezing, for example, the white background of printed fabrics was often dirtied. Due to the small amount of the squeezed out liquid, its removal and reintroduction at the proper place are facilitated and can take place with conduits having small diameters.

FIG. 3 shows a special plant constructed for solution washing, for example, after bleaching or mercerization. The washing effects depend primarily upon the manner of guiding the bath and the extent of the separation. Fresh water is introduced at 20 and flows in countercurrent through the first four sections. Each section contains two entirely separate baths. Used water is removed at 21. The main bath flow is indicated by the full line 22 while the flow of the squeezed out liquid is indicated by the broken line 23. The plant is provided with a heat exchanger.

In this example the last section which also has two separate baths, is supplied at 26 with water which has been made salt-free in an ionic exchanger and which after flowing through this section is added to the fresh water. The reason is that it was found that under certain conditions the desired wash effect, for example a pH value 4 of 8, can not be attained with the available fresh water even with the greatest expenditure of machine power. When salt-free water is used, however, the hydrolytic balance, for example in the case of caustic soda, is so shifted that even lower residual concentrations or pH values may be attained upon the fabric.

The concentrated separation of the squeezed out liquid provides an excellent possibility of measuring the wash effect by the conductivity of the squeezed out liquid, for example, by an instrument 25 which measures conductivity in order to regulate water consumption. There is a clear interrelationship between the concentrations of the chemicals in the fabric and in the squeezed out liquid. The measurements can be used to regulate values which influence the wash effect which are, for example, water consumption and speed of the fabric. The plant of FIG. 3 has a flow arrangement which is so constructed, for example, through the use of large flow cross sections, that the required countercurrent of the wash bath is assured by a bath level difference of only 10-12 mm. water column from one section to the other.

It is apparent that the examples described above have been given solely by way of illustration and not by way of limitation and that they are subject to many variations and modifications within the scope of the present invention. All such variations and modifications are to be included within the scope of the present invention.

What is claimed is:

1. In a process for the wet treatment of a moving length of material, in combination with a step of wet treating said length of material in several separate wet treating sections while passing said length consecutively through said treating sections, these steps of separately removing liquid from said length after its passage through each treating section while preventing said liquid from penetrating into a different treating section, causing a flow of a treating liquid in countercurrent to the direction of movement of said length, whereby there are at least from five to eight treating sections with at least eight separated baths, said step of separately removing the liquid comprising high output squeezing with 65 to squeezing which is carried out in two stages, the first stage consisting of a preliminary squeezing for the removal of surface liquid and the second stage consisting of main squeezing for the removal of more core liquid, and using the high concentration of the core liquid squeezed out in the last liquid removal for measuring the residual concentration of the treated liquid.

2. A process in accordance with claim 1, wherein said measuring is used for operating or regulating the treatments.

References Cited UNITED STATES PATENTS Patent No. 3,451,077

June 24 1969 Christian August Meier-Windhorst et al.

in the above identified It is certified that error appears hereby corrected as patent and that said Letters Patent are shown below: In the heading to the printed specification, lines 7 and 8 "Dr. Artos Ing. Meier-Windhorst K. G. should read Artos Dr.

Signed and sealed this 21st day of April 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer Ing. Meier-Windhorst K. G. 

